Electric furnace roof

Abstract

Electric furnace roof comprising key-arch-wedge refractory shapes contained in adjacent concentric rings within a roof band, expansion allowance means disposed between brick in both the radial and circumferential direction and spacer means disposed between brick in at least the radial direction.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. In a sprung electric furnace roof having downwardly-opening dish-shaped dome-type roof, said roof being fabricated of a plurality of key-arch-wedge refractory shapes contained in adjacent concentric rings within a roof band, said shapes having a hot face and a cold face, expansion allowance means disposed, substantially the entire distance, between brick in both the radial and circumferential direction, spacer means, disposed from the hot face to a relatively short distance above the hot face, between brick at least in the radial direction, said roof being devoid of any metal plating or suspension. 
     
     
       2. Roof of claim 1, in which the spacer means is also disposed between brick in the circumferential direction. 
     
     
       3. Roof of claim 1, in which the refractory shapes are of only two different sizes. 
     
     
       4. Roof of claim 1, in which the refractory shapes are composed of basic refractory material. 
     
     
       5. Roof of claim 1, in which the expansion and spacer means is composed of mineral or ceramic fiber.